The use of microbial bioherbicides in cultivated crops reached an impasse several decades ago. The three of us thought that the time had come to convene a conference to consider the reasons why so little progress has been made in development and commercialization of microbial bioherbicides and to discuss solutions to the impediments. This issue of Pest Management Science is largely composed of articles based on presentations given at this OECD-sponsored conference held on 26–28 September 2022 in Bari, Italy that was entitled ‘Overcoming the Barriers to Adoption of Microbial Bioherbicides’. Participants with a broad range of backgrounds and experiences with microbial bioherbicides were invited.